Due to the limited landmasses in the Southern Hemisphere, we must rely on data from sub-Antarctic islands within the Southern Ocean to record historical climate patterns. Over the past few decades, glaciers throughout the Southern Ocean region have experienced a noticeable retreat, especially in the Kerguelen Archipelago, whose glacial landforms offer valuable insights into long-term climate fluctuations. Our comprehensive glacial geomorphological study conducted in its remote north-western region meticulously examines morainic complexes from smaller cirque glaciers and larger outlet glaciers stemming from the Cook Ice Cap. We mapped these landforms to reconstruct historical glacier extents during the Holocene. The surface area of the three main glaciers had decreased in 1962–1964 by only 35% compared to their maximum extents, whereas surface area changes across 12 time intervals spanning from 1962 to 2019 from aerial and satellite imagery reveal a cumulative reduction of 43.5%. Additionally, we modelled changes in glacier thickness and equilibrium-line altitude for the key glaciers at three distinct stages: 1) their maximum extent before 1962, 2) the early 1960s and 3) 2019. This multifaceted analysis contributes valuable insights into the dynamics of Kerguelen's glaciers and the broader implications for understanding past and ongoing climate dynamics in the Southern Hemisphere.

To further elucidate the Late Pleistocene glacial history of mid-elevation mountainous regions in Central Europe, 10Be cosmic-ray exposure (CRE) dating was applied to moraines in the Zastler Tal Valley in the Southern Black Forest. Periods of glacier recession from moraines in this valley began no later than 16 ka, 15 ka, and 13 ka. CRE ages of moraines in this and other parts of the Southern Black Forest cluster around 17–16 ka and 15–14 ka, thus suggesting a common forcing of glacier recession. Equilibrium-line altitudes (ELAs) during moraine formation were calculated for precipitation reconstruction. Observed spatial discrepancies in ELAs at ca. 15–14 ka are explained best by the size of snow-contributing areas. The reconstructed annual precipitation at the ELA for ca. 16 ka and ca. 15 ka is affected by large uncertainties, representing a wide range from ~50% to ~150% of present-day values. Due to various factors, such as drifting snow, the lower bounds of the estimates appear most realistic, thus concurring with the common hypothesis of less precipitation during the last glacial termination than today in Central Europe. Further research is needed before ELAs of small ice masses can be employed for precise precipitation estimates.

Our limited knowledge of the climate prevailing over Europe during former glaciations is the main obstacle to reconstruct the past evolution of the ice coverage over the Alps by numerical modelling. To address this challenge, we perform a two-step modelling approach: First, a regional climate model is used to downscale the time slice simulations of a global earth system model in high resolution, leading to climate snapshots during the Last Glacial Maximum (LGM) and the Marine Isotope Stage 4 (MIS4). Second, we combine these snapshots and a climate signal proxy to build a transient climate over the last glacial period and force the Parallel Ice Sheet Model to simulate the dynamical evolution of glaciers in the Alps. The results show that the extent of modelled glaciers during the LGM agrees with several independent key geological imprints, including moraine-based maximal reconstructed glacial extents, known ice transfluences and trajectories of erratic boulders of known origin and deposition. Our results highlight the benefit of multiphysical coupled climate and glacier transient modelling over simpler approaches to help reconstruct paleo glacier fluctuations in agreement with traces they have left on the landscape.

Glaciers retreating in response to climate warming are progressively exposing primary mineral substrates to surface conditions. As primary production is constrained by nitrogen (N) availability in these emerging ecosystems, improving our understanding of how N accumulates with soil formation is of critical concern. In this study, we quantified how the distribution and speciation of N, as well as rates of free-living biological N fixation (BNF), change along a 2000-year chronosequence of soil development in a High Arctic glacier forefield. Our results show the soil N pool increases with time since exposure and that the rate at which it accumulates is influenced by soil texture. Further, all N increases were organically bound in soils which had been ice-free for 0–50 years. This is indicative of N limitation and should promote BNF. Using the acetylene reduction assay technique, we demonstrated that microbially mediated inputs of N only occurred in soils which had been ice-free for 0 and 3 years, and that potential rates of BNF declined with increased N availability. Thus, BNF only supports N accumulation in young soils. When considering that glacier forefields are projected to become more expansive, this study has implications for understanding how ice-free ecosystems will become productive over time.

With the conclusion of the Last Glacial Maximum (LGM), about 20 000 years ago, ended the most recent long-lasting cold phase in Earth history. This last glacial advance left a strong observable imprint on the landscape, such as moraines, trimlines and other glacial geomorphic features. These features reflect the extent of former glaciers and ice caps, which in turn provides information on past temperature and precipitation conditions. Here we present an inverse approach to reconstruct the equilibrium line altitudes (E) from observed ice extents. The ice-flow model is developed solving the mass conservation equation using the shallow ice approximation and implemented using Graphical Processing Units (GPUs). We present the theoretical basis of the inversion method, which relies on a Tikhonov regularization, and demonstrate its ability to constrain spatial variations in mass balance with idealized and real glaciers.

Lichenometry accurately dates exposure times of glacial moraines and landslides when measuring the longest axis of the largest crustose lichen on many blocks, as demonstrated by numerous examples. In Sweden, the sizes of Rhizocarpon subgenus Rhizocarpon describe five pulses of glacial moraine creation in 120 yr. Six historic California earthquakes, between AD 1800 and 1906, caused many landslides that constrain lichen growth as linear with a dating accuracy of±0.5 yr. Crustose lichen sizes date earthquake-created additions to Sierra Nevada talus with an accuracy of±5 yr. The oldest lichen ages are 400 yr for Lecanora sierrae, 800 yr for Lecidea atrobrunnea, and 1100 yr for Acarospora chlorophana and Rhizocarpon subgenus Rhizocarpon. Lichen sizes also record differing spatial attenuation of ground shaking from the magnitude (Mw) ~7.9 San Andreas earthquake of AD 1857 and the more distant, smaller San Jacinto AD 1800 earthquake, which both caused Sierra Nevada rockfalls. AD 1800 seismic shaking was relatively stronger than that of AD 1857 farther north, perhaps expressing stronger Love and Rayleigh styles of surface waves from the north-trending AD 1800 surface rupture that were particularly efficient in causing rockfalls at greater distances.

In glacial environments particle-size analysis of moraines provides insights into clast origin, transport history, depositional mechanism and processes of reworking. Traditional methods for grain-size classification are labour-intensive, physically intrusive and are limited to patch-scale (1 m2) observation. We develop emerging, high-resolution ground- and unmanned aerial vehicle-based ‘Structure-from-Motion’ (UAV-SfM) photogrammetry to recover grain-size information across a moraine surface in the Heritage Range, Antarctica. SfM data products were benchmarked against equivalent datasets acquired using terrestrial laser scanning, and were found to be accurate to within 1.7 and 50 mm for patch- and site-scale modelling, respectively. Grain-size distributions were obtained through digital grain classification, or ‘photo-sieving’, of patch-scale SfM orthoimagery. Photo-sieved distributions were accurate to <2 mm compared to control distributions derived from dry-sieving. A relationship between patch-scale median grain size and the standard deviation of local surface elevations was applied to a site-scale UAV-SfM model to facilitate upscaling and the production of a spatially continuous map of the median grain size across a 0.3 km2 area of moraine. This highly automated workflow for site-scale sedimentological characterization eliminates much of the subjectivity associated with traditional methods and forms a sound basis for subsequent glaciological process interpretation and analysis.

Analyses of all published cosmogenic exposure ages for moraine boulders show an average age range of 38% between the oldest and youngest boulders from each moraine. This range conflicts with the common assumption that ages of surface boulders are the same as the age of the landform. The wide spread in boulder ages is caused by erosion of the moraine surface and consequent exhumation of fresh boulders. A diffusion model of surface degradation explains the age range and shows that a randomly sampled small set of boulders (n = 3–7) will always yield a lower age limit for the moraine. The model indicates that for identical dating accuracy, six to seven boulders are needed from old and tall moraines (40,000–100,000 yr, 50–100 m initial height) but only one to four boulders from small moraines (20,000–100,000 yr, 10–20 m). By following these guidelines the oldest obtained boulder age will be ≥90% of the moraine age (95% probability). This result is only weakly sensitive to a broad range of soil erosion rates. Our analysis of published boulder ages indicates that <3% of all moraine boulders have prior exposure, and 85% of these boulders predate the dated moraine.

The statistical distributions of cosmogenic nuclide measurements from moraine boulders contain previously unused information on moraine ages, and they help determine whether moraine degradation or inheritance is more important on individual moraines. Here, we present a method for extracting this information by fitting geomorphic process models to observed exposure ages from single moraines. We also apply this method to 94 10Be apparent exposure ages from 11 moraines reported in four published studies. Our models represent 10Be accumulation in boulders that are exhumed over time by slope processes (moraine degradation), and the delivery of boulders with preexisting 10Be inventories to moraines (inheritance). For now, we neglect boulder erosion and snow cover, which are likely second-order processes. Given a highly scattered data set, we establish which model yields the better fit to the data, and estimate the age of the moraine from the better model fit. The process represented by the better-fitting model is probably responsible for most of the scatter among the apparent ages. Our methods should help resolve controversies in exposure dating; we reexamine the conclusions from two published studies based on our model fits.

The ablation areas of debris-covered glaciers typically consist of a complex mosaic of surface features with contrasting processes and rates of mass loss. This greatly complicates glacier response to climate change, and increases the uncertainty of predictive models. In this paper we present a series of high-resolution DEMs and repeat lake bathymetric surveys on Ngozumpa Glacier, Nepal, to study processes and patterns of mass loss on a Himalayan debris-covered glacier in unprecedented detail. Most mass loss occurs by melt below supraglacial debris, and melt and calving of ice cliffs (backwasting). Although ice cliffs cover only ~5% of the area of the lower tongue, they account for 40% of the ablation. The surface debris layer is subject to frequent re-distribution by slope processes, resulting in large spatial and temporal differences in debris-layer thickness, enhancing or inhibiting local ablation rates and encouraging continuous topographic inversion. A moraine-dammed lake on the lower glacier tongue (Spillway Lake) underwent a period of rapid expansion from 2001 to 2009, but later experienced a reduction of area and volume as a result of lake level lowering and sediment redistribution. Rapid lake growth will likely resume in the near future, and may eventually become up to 7 km long.

The origin of Illinois Episode (OIS 6) glacial ridges (formerly: ‘Ridged Drift’) in the Kaskaskia Basin of southwestern Illinois is controversial despite a century of research. Two studied ridges, containing mostly fluvial sand (OSL ages: ~ 150 ± 19 ka), with associated debris flows and high-angle reverse faults, are interpreted as ice-walled channels. A third studied ridge, containing mostly fine-grained till, is arcuate and morainal. The spatial arrangement of various ridge types can be explained by a glacial sublobe in the Kaskaskia Basin, with mainly fine-grained ridges along the sublobe margins and coarse-grained glaciofluvial ridges in a paleodrainage network within the sublobe interior. Illinois Episode till fabric and striation data demonstrate southwesterly ice flow that may diverge near the sublobe terminus. The sublobe likely formed as glacial ice thinned and receded from its maximum extent. The Kaskaskia Basin contains some of the best-preserved Illinois Episode constructional glacial landforms in the North American midcontinent. Such distinctive features probably result from ice flow and sedimentation into this former lowland, in addition to minimal postglacial erosion. Other similar OIS 6 glacial landforms may exist in association with previously unrecognized sublobes in the midcontinent, where paleo-lowlands might also have focused glacial sedimentation.

During fieldwork of the 1998–99 and 1999–2000 Chinese National Antarctic Research Expedition (CHINARE), three different kinds of Cenozoic sedimentary record were found in the Grove Mountains, which are in East Antarctica about 450km inland of Prydz Bay. These consist of (1) glaciogenic sedimentary erratics found in the moraine banks in the central area of Grove Mountains, which can be subdivided into four types according to different degrees of lithification as well as differences in inner structure and include in-situ diamicts; (2) palaeosols found in several small depressions in the southern slope of the Mount Harding; and (3) different kinds of glacial moraine floating on the surface of blue ice or around the foot of some nunataks. Preliminary results suggest that the in situ glaciogenic sediments were formed in the ice-sheet frontal area by the interaction of glacial movement and ice sheet melt water under climatic conditions warmer than today.

The extent of 64 glaciers that existed in the Lake District during the Loch Lomond Stadial is inferred from end, hummocky and fluted moraines and illustrated by detailed maps. Glacier surfaces are contoured and the equilibrium firn lines of the glaciers are calculated. Firn line altitudes were strongly influenced by snowfall, glacier aspect and the transfer of snow by wind from adjacent high ground. Snowfall was associated mainly with south to southeast winds and the mean direction of winds responsible for snow transfer was probably slightly west of south. It is inferred that mean July temperature at sea-level was slightly below 8°C. Protalus ramparts and other snowbed deposits indicate the former presence of numerous perennial snow beds down to altitudes of 200-300 m although the widespread occurrence of fossil gelifluction sheets and lobes points to large snow-free areas above these altitudes in summer. Fossil valley-wall rock glaciers indicate a mean annual temperature at sea-level no higher than 1°C. During deglaciation the great majority of the small glaciers retreated actively for 100-150 m and then probably decayed in situ, but some, at least, of the larger glaciers were active during much of the time their margins retreated.